Fix #2924. IfcElements default to a null predefined type so they can inherit where possible.

src/ifcopenshell-python/ifcopenshell/api/root/create_entity.py

@@ -100,7 +100,7 @@ class Usecase:
         return element
 
     def handle_2x3_defaults(self, element):
-        if element.is_a("IfcElement") or element.is_a("IfcElementType"):
+        if element.is_a("IfcElementType"):
             if hasattr(element, "PredefinedType") and not element.PredefinedType:
                 element.PredefinedType = "NOTDEFINED"
 
@@ -117,7 +117,7 @@ class Usecase:
             element.Sizeable = False
 
     def handle_4_defaults(self, element):
-        if element.is_a("IfcElement") or element.is_a("IfcElementType"):
+        if element.is_a("IfcElementType"):
             if hasattr(element, "PredefinedType") and not element.PredefinedType:
                 element.PredefinedType = "NOTDEFINED"
 

src/ifcopenshell-python/test/api/root/test_create_entity.py

@@ -32,7 +32,7 @@ class TestCreateEntity(test.bootstrap.IFC4):
 
     def test_handling_predefined_types(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall", name="Foo")
-        assert element.PredefinedType == "NOTDEFINED"
+        assert element.PredefinedType is None
         element = ifcopenshell.api.run(
             "root.create_entity", self.file, ifc_class="IfcWall", predefined_type="SHEAR", name="Foo"
         )
@@ -54,6 +54,8 @@ class TestCreateEntity(test.bootstrap.IFC4):
         assert element.ProcessType == "Foobar"
 
     def test_setting_default_values_for_validity(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType", name="Foo")
+        assert element.PredefinedType == "NOTDEFINED"
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDoorStyle", name="Foo")
         assert element.OperationType == "NOTDEFINED"
         assert element.ConstructionType == "NOTDEFINED"